1. Field of the Invention
The present invention relates to a method of manufacturing mounting boards comprising mounting electronic parts in stacked multiple levels on a substrate.
2. Description of the Related Art
In recent years, electronic devices such as cell phones and video cameras are rapidly becoming smaller and more sophisticated. In such a trend, the mounting board constituting the electronic circuits of those electronic devices are requested to have still higher packaging densities. To meet the requirement of packaging density enhancement for mounting boards, semiconductor packages having electronic parts stacked in the vertical direction are being used (Refer to, for example, Japanese Patent Laid-open No. 2002-217359).
With the adoption of semiconductor packages of such a stacked structure, manufacture of function-enhanced mounting boards is possible without increasing the board size.
However, the semiconductor package set forth in the preceding techniques cited above is manufactured by combining plural electronic parts whereby complicated steps are needed including the inspection of operation as a stacked structure during the development of such semiconductor elements. Accordingly, a considerably long period has been needed for the development of a semiconductor device as an individual electronic part. Due to such background, the types of the electronic parts to be used in a semiconductor package of stacked structure have been rather limited, and thus it was difficult to adopt the stacked structure in various applications at a low cost.